How to Recharge Your Car's Air Conditioner By Larry Carley c2007 LOW REFRIGERANT If your air conditioner is not cooling well because the system is low on refrigerant, recharging the system with refrigerant should restore normal operation. This can usually be done with a few cans of refrigerant and a simple service hose connection. RECHARGING PRECAUTIONS First, wear safety glasses to protect your eyes. Also avoid skin contact with refrigerant. The chilling effect of spilled refrigerant can cause instant frostbite on bare skin or eyes! WHAT TYPE OF REFRIGERANT? Next, you need to figure out what type of refrigerant your vehicle requires:
On 1995 and newer passenger cars and light trucks, the correct refrigerant is R134a. DO NOT use any other type of refrigerant.
On most 1994 and older passenger cars and light trucks, the original refrigerant was R12. R12 is no longer available to do-it-yourselfers and is very expensive. When older vehicles with R12 A/C systems need refrigerant, they can be refilled with recycled R12 from other older cars (this requires taking your car to a repair shop for professional service), or with some alternative refrigerant other than R12, or with R134a (which requires certain modifications). CAUTION: Mixing different types of refrigerants is NOT recommended. Use the same type of refrigerant that is already in the system unless you are converting an older R12 system to R134a or another refrigerant. WARNING: Flammable refrigerants are illegal. DO NOT use any type of flammable refrigerant (propane, butane or flammable hydrocarbons). Click here for more information about retrofitting older vehicles with R12 A/C systems to R134a. LOCATE THE SERVICE FITTINGS Next, you need to locate the service fittings on the A/C system. There are two: a LOW side fitting and a HIGH side fitting. The LOW side fitting is usually located on the suction hose or line that goes from the accumulator to the compressor. The HIGH side fitting is located on the line that goes from the compressor to the condenser. R12 Low Side 7/16 in. threaded ÃŸ----------Ã R134 Low Side 13mm Quick-disconnect R12 High Side 3/8 in. threaded ÃŸ----------Ã R134A High Side 16mm Quick-disconnect On older R12 systems, the LOW and HIGH pressure service fittings are screw-type Schrader valves. On newer R134a systems, the LOW and HIGH side service fittings are quick-connect style fittings. The LOW pressure fitting is SMALLER than the HIGH pressure fitting. RECHARGE PROCEDURE 1. Connect the recharge service hose and valve to a can of refrigerant.
2. Turn the valve on the service hose to puncture the top of the can.
3. SLOWLY turn the valve back out to release a small amount of refrigerant into the hose. This will blow air out of the hose (which you do not want in your A/C system).
4. Close the valve so no more refrigerant escapes, then quickly connect the other end of the service hose to the LOW pressure service fitting on the A/C system.
CAUTION: DO NOT connect a can of refrigerant to the HIGH side service fitting. The operating pressure inside the A/C system when it is running may exceed the burst strength of the can, causing the can to explode! This should be impossible to do because the service hose for recharging the A/C system will only fit the smaller LOW pressure service fitting. Even so, you should be aware of the danger.
5. Hold the can UPRIGHT so no refrigerant liquid enters the service hose. You only want VAPOR to be pulled into the A/C system (the compressor may be damaged if it sucks in a big dose of liquid!).
6. OPTIONAL BUT HIGHLY RECOMMENDED: You should use a gauge to monitor the recharging process. Though not absolutely necessary, a gauge will help you recharge your A/C system more accurately, and reduce the chance of undercharging or overcharging (either of which will reduce cooling performance).
A high pressure A/C gauge can be connected to the HIGH pressure service fitting, or a low pressure A/C gauge to the LOW pressure service fitting, or gauges can be attached to both fittings (that is what professional technicians do).
NOTE: Some DIY recharging kits include a low pressure gauge on the service hose or on a trigger-grip style can dispenser.
7. Start the engine and turn the A/C on MAX/HIGH.
8. NOTE: The compressor may not engage if the system is too low on refrigerant. The low pressure cutout switch will prevent the compressor from running if the system is too low on refrigerant (this is done to protect the compressor from damage due to a lack of proper lubrication). The compressor must be running to suck refrigerant through the service hose into the system. So if it is not engaging when you turn the A/C on, you may have to supply battery voltage directly to the compressor clutch using a fused jumper wire. Look for a single wire connector near the front of the compressor, unplug it and hook up a jumper wire to the battery POSITIVE terminal. This should cause the clutch to engage and the compressor to run.
9. OPEN the valve on the service hose so refrigerant vapor will flow from the can into the A/C system. It may take up to 10 minutes or more per can to suck all of the refrigerant out of the can into the A/C system. Feel the air coming out of the ducts inside the vehicle. It should be getting colder.
10. If you are using a high or low pressure gauge (or both) to monitor recharging, look at the gauge(s).
LOW pressure gauge: When the reading is between 25 and 40 psi with the A/C running, STOP. The system is fully charged and should be cooling normally. DO NOT add any more refrigerant. If the gauge is over 50 psi, you have overcharged the system with too much refrigerant.
High pressure gauge: When the reading gets up around 200 to 225 psi (R12), or225 to 250 psi (R134a), STOP. The system is fully charged and should be cooling normally. DO NOT add any more refrigerant.
NOTE: The high and low pressure readings will vary depending on the system and ambient temperatures (higher temperatures cause higher system pressure readings).
Refer to the vehicle manufacturer specifications for normal system operating pressures, and the total refrigerant capacity of the system. Most newer passenger car A/C systems do not hold much refrigerant (only 14 to 28 oz.), so you don't want to add too much if the system is low. One can of R134a typically holds 12 oz. of refrigerant.
11. If the system needs more refrigerant after adding one can, you can add a second can. CLOSE the valve on the service hose, then disconnect the hose from the empty can, screw a new can onto the service hose valve, turn the valve to puncture the new can, then turn the valve all the way back out again so refrigerant can flow through the hose into the A/C system.
When you have finished, turn the engine off. CLOSE the valve on the can of refrigerant before disconnecting the service hose from the LOW pressure fitting (in case there is any refrigerant left in the can). Don't vent any leftover refrigerant from the can. Leave the service hose attached to the can with the valve closed so you can save the refrigerant for a future recharge.
Remember to replace the plastic caps over the service fittings, and remove the jumper wire from the compressor if you had to jump it to make it run. IF THE A/C SYSTEM STOPS BLOWING COLD AIR AFTER A FEW DAYS, WEEKS OR MONTHS If your A/C stops blowing cold air several days, weeks or months after you recharged it, it means the system has a leak and the refrigerant is escaping. You should add some leak detection dye to the system to find the leak. The leak should then be repaired before the system is recharged again; otherwise you are just wasting your time recharging the system over and over again. http://www.aa1car.com/library/ac_recharging.htm
It has an oil pressure switch whose only purpose is to turn an indicator light on if the oil pressure is too low. The switch is located on the back of the block.It has an oil pressure switch whose only purpose is to turn an indicator light on if the oil pressure is too low. The switch is located on the back of the block.
The low pressure cutoff switch on the air condition system of a 2001 Honda Accord is located towards the front of the engine compartment. The unit is placed on the refrigerant reservoir.
The 1994 Pontiac Trans Am air conditioning low pressure switch is on top of the air conditioner compressor. The low pressure switch will be labeled as the low pressure port.
Low oil pressure or failed oil pressure switch.
Of which low pressure switch are you speaking? Engine oil pressure switch? If you're checking that, remove the oil pressure sending unit and temporarily put in an oil pressure gauge. If you're checking the AC low pressure switch, pull the switch from the AC low pressure line, Jumper the switch socket and see if the AC compressor comes on. If it does, you either have low refrigerant pressure or a bad switch. If you KNOW the pressure is up and everything else works, you have a bad switch.
It means that the oil pressure switch is showing low pressure.
The 1997 Pontiac Sunfire air conditioning low pressure switch can be found on the top of the air conditioning compressor. The low pressure switch will be labeled as the low pressure port.
The 1997 Toyota Avalon air conditioning low pressure switch can be found on the top of the air conditioning compressor. The low pressure switch will be labeled as the low pressure port.
The low pressure switch is mounted near the ac compressor. It is a two wire switch mounted in the low side line.
There is no manual low pressure switch but there is a low pressure switch that turns on the oil light and shuts off the fuel pump to prevent the engine from running with no oil pressure.
on a 2005 Honda Accord where is the low pressure AC switch
This vehicle does not have a low pressure switch. It has a pressure transducer instead. The pressure transducer is located on the refrigerant line next to the alternator pulley.
A pressure switch a valve that shuts off the unit when the pressure is to low or to high
You can bypass the AC low pressure switch, on your Toyota Corolla, by removing the switch. You can remove the wiring to the switch and leave the switch and place.
no but its on the same line
TThe low pressure AC switch is a 3-way pressure switch in the low-side refrigerant line. It is open when the pressure is approximately below 27 psi and above 350 psi and closed when the pressures are in between.
On my service DVD i cant seem to find a low pressure switch. i did find a AC refrigerant pressure switch i dont knwo if its the same
Low on freon, faulty pressure switch, faulty clutch. Jumper the low pressure switch with a paperclip (can running, AC on), if the clutch cycles, it's either low on freon, or the low pressure switch is bad.
If you are speaking of the AC low pressure switch, It is behind the passenger side head light on top of dryer!
Trouble code P0452 means: Evaporative Emission System Pressure Sensor/Switch Low Input
There is an Aluminum tank on the passenger side of the engine compartment. The low pressure switch is usually mounted to and tucked behind it.
The AC low pressure switch of a Honda Civic is located on the driver's side of the radiator. It is screwed into the accumulator bottle.
The low oil cut off switch should be on the side of the oil pan. It is built into the oil pressure switch.
It seems reasonable to assume that the low-pressure switch opens the circuit to the Compressor/Clutch when it senses low pressure in the system. So higher pressure must close it, making it a normally-open switch. Nevin Hawlman GardenGrapevine.com
The low pressure switch is usually on either the h valve, accumulator, or in the suction line.